Since S/PDIF doesn’t provide any content protection, Vista requires that it be disabled when playing protected content [Note D]. In other words if you’ve sunk a pile of money into a high-end audio setup fed from an S/PDIF digital output, you won’t be able to use it with protected content.

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So if you’re using an expensive new LCD display fed from a high-quality DVI signal on your video card and there’s protected content present, the picture you’re going to see will be, as the spec puts it, “slightly fuzzy”, a bit like a 10-year-old CRT monitor that you picked up for $2 at a yard sale.

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Most hardware vendors have (thankfully) moved to unified driver models instead of the plethora of individual drivers that abounded some years ago. Since HFS requires unique identification and handling of not just each device type (for example each graphics chip) but each variant of each device type (for example each stepping of each graphics chip) to handle the situation where a problem is found with one variation of a device, it’s no longer possible to create one-size-fits-all drivers for an entire range of devices like the current Catalyst/Detonator/ForceWare drivers. Every little variation of every device type out there must now be individually accommodated in custom code in order for the HFS process to be fully effective.